package demo.practice.leetcode;


import java.util.LinkedList;
import java.util.Stack;

public class StackAndQueue {

    public static void main(String[] args) {
        LinkedList<TreeNode> list = new LinkedList<>();
        list.add(null);
        System.out.println(list.size());
        System.out.println(list.poll());


        Stack<TreeNode> nds = new Stack<>();
        nds.add(null);
        System.out.println(nds.size());
        System.out.println(nds.pop());
    }
}
